This sample trick - a brain teaser - from the first page of the book. Four other tricks can be seen by clicking on the table of contents links for the book below.

An Old Favorite

This old-timer has puzzled people for many years. There are three houses to be supplied with water from three hydrants-one hydrant to each house. Call the hydrants 1, 2 and 3, and the houses 1, 2, and 3.

Now the problem is as follows:
Run pipes (pencil lines) from hydrant 1 to house 1, from hydrant 2 to house 2, and from hydrant 3 to house 3, without crossing any of the lines. You must not go above any of the hydrants. Solution will be found on below.